A series of Israeli airstrikes in Gaza killed four Hamas militants early today, raising the Palestinian death toll in the past day to 15, including a baby.
It raised the spectre of a serious escalation of Israel-Hamas fighting a day after a rocket fired from Gaza killed an Israeli.
Hamas claimed responsibility for the deadly rocket blast yesterday at Sapir College in the town of Sderot, killing a student in a parking lot. He was identified by Israeli media as a 47-year-old father of four.
Hitting back, Israeli planes blasted the office of Hamas prime minister Ismail Haniyeh and the Interior Ministry, which were empty.
Mr Haniyeh and other Hamas leaders have been in hiding, fearing Israeli assassination attempts.
Palestinian health officials said a six-month-old baby was killed and about 30 residents of nearby buildings were hurt in the Israeli attack.
Overnight, the Israeli army said it carried out three more airstrikes against militants in northern Gaza. Palestinian officials reported four dead in the attacks.
At least 40 rockets were fired at Israel from Gaza on Wednesday, the military said, many more than the average of daily barrages that have disrupted life in the region.